Pervious Pavement Designs to Control Urban Flooding and Pollution
May 2014 - March 2015
Urban flooding following intense rainfall can be partly managed by the installation of water management infrastructure including Sustainable Drainage Systems (SuDS). Coventry University is a worldwide centre of excellence in the design, testing and impact assessment of novel drainage infrastructure. In this project, Marshalls, the UK’s leader in hard engineered SuDS, asked the CAWR water research team to investigate new designs for permeable paving that improved performance in terms of flood management and water quality. New designs under test included a bespoke geotextile for water purification and a Coventry University patented barrier design to absorb additional flood water and treat oil pollution.
The research team worked with Marshalls to design, construct and commission the permeable pavement models at Marshalls Marketing Support Unit in Halifax, Yorkshire, UK. The models represented a credible simulation of field conditions, being of sufficient size to be representative of a real permeable pavement, but with a controllable simulation of environmental conditions as the models were located within the CAWR Water Lab at the University. The models were around a cubic metre in volume and weighed around a tonne each. As there were 13 of the models, it was a considerable logistical undertaking to transport them 140 miles to Coventry University and position them in the laboratory.
Research is ongoing, but pilot results showed that the new geotextile design and the new Coventry University design worked well as a filtration media when compared with no barrier layer. The concentration of dissolved metals including zinc, lead, aluminium, copper and cadmium in water discharged from the model systems was lower in the presence of the new barrier layers relative to the current standard design. Both the total volume of discharged water and the rate of discharge were improved with the use of the new CU barrier as an absorbent medium.
It was demonstrated by microbiological investigation, that bacteria fungi and other microbes were growing in abundance within the models and reducing the level of oil contamination, reducing the risk of pollution from discharge.
This research is in the forefront of the optimisation of urban drainage infrastructure, to improve the resilience of urban environments against future flood events and potentially a more extreme climate.
For more information on this project please contact Dr Steve Coupe
(l-r) Chris Griffiths of Marshalls, with Steve Coupe,
Dr Luis Sañudo Fontaneda and Ann-Marie McLaughlin of CAWR